Waldorf Q Rack, User Manual

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Appendix – Glossary
161 Waldorf Q User’s Manual
Glossary
Aftertouch
The majority of contemporary keyboards are capable
of generating aftertouch messages. On this type of
keyboard, when you press harder on a key you are
already holding down, a MIDI Aftertouch message is
generated. This feature makes sounds even more
expressive (e.g. through vibrato).
Aliasing
Aliasing is an audible side effect arising in digital
systems as soon as a signal contains harmonics higher
than half the sampling frequency.
Amount
Describes to which extent a modulation influences a
given parameter.
Amplifier
An amplifier is a component that influences the
volume level of a sound via a control signal. This
control signal is often generated by an envelope or an
LFO.
Arpeggiator
An arpeggiator is a device that splits an incoming
MIDI chord into its single notes and repeats them
rhythmically. Most arpeggiators feature different
sequence modes to cover a wide range of
applications. Typical controls for an arpeggiator are
the octave range, the direction, the speed and the
clock, which means the repetition interval. Some
arpeggiators also feature preset or programmable
rhythm patterns.
Attack
An envelope parameter. "Attack" is a term that
describes the ascent rate of an envelope from its
starting point to the point where it reaches its highest
value. The Attack phase is initiated immediately after
a trigger signal is received, i.e. after you play a note
on the keyboard.
Band Pass Filter
A band pass filter allows only those frequencies
around the cutoff frequency to pass. Frequencies both
below and above the cutoff point are damped.
Band Stop Filter
A band stop filter does the opposite to a band pass
filter, i.e. it dampens only the frequencies around the
cutoff point and lets all other frequencies pass
through.
Clipping
Clipping is a sort of distortion that occurs when a
signal exceeds its maximum value. The curve of a
clipped signal is dependent of the system where the
clipping takes place. In the analog domain, clipping
works like limiting the signal to its maximum level. In
the digital domain, clipping is similar to a numerical
overflow and so the polarity of the signal’s part above
the maximum level is negated.
Control Change (Controllers)
MIDI messages enable you to manipulate the
response of a sound generator to a significant degree.
This message essentially consists of two components:
• The Controller number, which defines the element
to be influenced. It can be between 0 and 120.
• The Controller value, which determines the extent
of the modification.
Controllers can be used for effects such as slowly
swelling vibrato, changing the stereo panorama
position and influencing filter frequency.
CV
CV is the abbreviation for control voltage. In analog
synthesizers, control voltages are used to control
sound parameters like pitch, cutoff frequency etc. E.g.
to get a tremolo effect, the output signal of a LFO
must be routed to the CV input of an (or several)
oscillator(s).
Decay
"Decay" describes the descent rate of an envelope
once the Attack phase has reached its zenith and the
envelope drops to the level defined for the Sustain
value.
Filter
A filter is a component that allows some of a signal's
frequencies to pass through it and dampens other
frequencies. The most important aspect of a filter is
the filter cutoff frequency. Filters generally come in
four categories: low pass, high pass, band pass, and
band stop. A low pass filter dampens all frequencies
above the cutoff frequency. A high pass filter in turn